Utilization of alanine for glucose formation in isolated rabbit kidney‐cortex tubules

FEBS Letters

Bryła, Jadwiga¹  Zabłocki, Krzysztof¹ 

[1] Institute of Biochemistry, University of Warsaw, Al. Zwirki i Wigury 93, PL 02-089 Warszawa, Poland

关键词: Alanine;    Gluconeogenesis;    (Rabbit renal tubule);   

DOI  :  10.1016/0014-5793(89)81514-5

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

In kidney cortex tubules isolated from fed rabbits L-alanine is not utilized as glucose precursor, when added as a sole substrate. However, this amino acid decreases gluconeogenesis from low (up to 1 mM) 2-oxoglutarate concentrations and stimulates this process at higher (2.5–10 mM) ketoacid contents in the suspension medium. Aminooxyacetate, an inhibitor of aminotransferases, abolishes both inhibitory and stimulatory effects of L-alanine on glucose formation. The addition of 2-oxoglutarate increases the incorporation of L-[U-¹⁴C]alanine to glucose from 8- to 123-fold, depending upon the ketoacid and alanine concentrations used. In contrast, nonlabelled L-alanine decreases the incorporation of low [U-¹⁴C)2-oxoglutarate concentrations into glucose, while it does not affect contribution of 5 mM ketoacid to gluconeogenesis. The data indicate that (i) in the presence of 2-oxoglutarate L-alanine is utilized as glucose precursor in rabbit renal tubules and (ii) this amino acid may decrease the contribution of low extracellular concentrations of the ketoacid to gluconeogenesis.

【 授权许可】

Unknown